What would be the best way to include babel-polyfill for a sapui5 project?

Hi experts,

We are building an application using sapui5 and using a grunt setup used and recommended by openui5. When we run 'grunt build' which builds our project by copying over our files to a library called target and creates the preload.js files it also uses babel to compile es6/7/8 to es5. Unfortunately, promises are not compiled so we would need babel-polyfill. We would like to add babel-polyfill to the project so we could use the latest features of javascript. We would like to add babel-polyfill via the build process if possible as adding another script tag to the project would cause the application the load slower.

Thank you for your advice in advance.

Kind Regards,

Tamas